You want to leave - How much notice you must give?
This depends on the type of tenancy agreement and the ground for termination (if any) – see table.
A fixed-term agreement is for a specified period (e.g. 6 months). A periodic agreement is one where the fixed-term has expired or no fixed term is specified. If you serve a termination notice by post, you must allow an extra 4 working days for delivery.
Immediate notice if premises are unusable
You can give immediate notice if the premises are destroyed, become wholly or partly unusable (other than due to a breach of the tenancy agreement), cease to be lawfully usable as a residence or are appropriated by a compulsory process.